Fig. 1.

Diagnostic procedures. This shows the diagnostic process flow at two time points: at enrolment and 3 years later. Initially, local diagnoses are made by each registration facility (Diagnosis 0). Next, central MDD members’ diagnoses are made by individual respiratory physicians, thoracic radiologists, and pulmonary pathologists (if pathological samples are available), independently (Diagnosis 1 to 3). Next, the MDD is conducted in two stages: first, by a respiratory physician and a radiologist (shown as MDD (CR) and Diagnosis 4), and if pathology samples are available, by including a pulmonary pathologist in the second stage (shown as MDD (CRP) and Diagnosis 5). Abbreviations: MDD, multidisciplinary discussion.; CR, clinical and radiological discussion; clinical, radiological, and pathological discussion